Test from a different network

If you can connect the computer to another network that doesn't have a firewall, you can try testing your SSH connection to GitHub. If everything works as it should, contact your network administrator for help on changing the firewall settings to allow your SSH connection to GitHub to succeed.

Using SSH over the HTTPS port

If using HTTPS is not an option, and your firewall admin refuses to allow SSH connections, you can try using SSH over the HTTPS port instead.